Definition: Central neurocytoma is a tumor of young adults composed of uniform round cells with neuronal differentiation, typically occurring in the lateral ventricles in the region of the foramen of Monro. Central neurocytoma corresponds to WHO Grade II.
Epidemiology: Central neurocytoma represents less than 1% of all intracranial tumors, with a peak in young adults between 20 and 40 years of age. Both sexes are affected equally.
Localization: Central neurocytoma is most commonly found in the anterior portion of the lateral ventricle (50%), followed by a combined presentation in the lateral and 3rd ventricles (15%), or biventricular location (13%). Only 3% of cases occur in the 3rd ventricle alone.
Clinical presentation: Patients with central neurocytoma typically present with signs and symptoms of increased intracranial pressure.
Imaging: MRI shows a moderately to strongly enhancing intraventricular lesion that has normal to high signal intensity on both T1- and T2-weighted imaging. Angiography demonstrates homogeneous vascular staining, with a blush persisting late in to the venous phase.
Macroscopy: These intraventriciular tumors are usually grayish and friable, with variable degrees of calcification and intratumoral hemorrhage.
Histopathology: Central neurocytoma is a neuroepithelial tumor composed of uniform round cells with neuronal differentiation, with adjacent fibrillary areas mimicking neuropil. Synaptophysin is the most reliable diagnostic marker. The low proliferation rate is generally low. In rare cases, anaplastic histological features may be seen.
Prognosis: The clinical course of central neurocytoma is usually benign. The management of patients with subtotal resection remains unclear, though it appears that these patients have shorter local control and survival rates. Interestingly, aggressive histological appearance does not seem to predict poor clinical outcome.